JP5235715B2 - Electric storage device and manufacturing method thereof - Google Patents

Abstract

A negative electrode mixture member (26) accommodated in a bag-like separator (18) includes a negative electrode (15) provided with a negative electrode current collector (23) and a negative electrode mixture layer (24) formed on one surface of the negative electrode current collector (23), and a metal lithium foil (16) adhered onto the negative electrode (15). Accordingly, even when metal lithium is dropped from the negative electrode current collector (23) of the negative electrode (15), the diffusion of the metal lithium in the electric storage device (10) can be prevented. Consequently, short-circuiting in the electric storage device (10) or corrosion of the outer casing (11) caused by the free metal lithium can be prevented, whereby the safety of the electric storage device (10) can be enhanced. Even when the metal lithium is dropped from the negative electrode current collector (23) of the negative electrode (15), the metal lithium can be retained in the vicinity of the negative electrode (15).

Description

  The present invention relates to an electricity storage device in which a negative electrode composite having an ion supply source is incorporated, and a method for manufacturing the same.

  Examples of power storage devices mounted on electric vehicles and hybrid vehicles include lithium ion capacitors and lithium ion secondary batteries. In order to improve the energy density of these electricity storage devices, an electricity storage device in which metallic lithium as an ion supply source is incorporated in the electricity storage device has been proposed. In this electricity storage device, metallic lithium is electrochemically connected to the negative electrode, and lithium ions are doped from the metallic lithium to the negative electrode. By performing charging / discharging between the positive and negative electrodes thereafter, it is possible to reduce the capacity loss of the electricity storage device when a negative electrode active material having a large irreversible capacity is used for the negative electrode. Further, by doping lithium ions into the negative electrode, it is possible to reduce the negative electrode potential in the charged or discharged state of the electricity storage device. That is, the average voltage of the electricity storage device can be increased by lowering the average potential of the negative electrode. As a result, the energy density of the electricity storage device can be improved. Further, as a method of incorporating metallic lithium into the electricity storage device, a method of attaching metallic lithium foil to the negative electrode current collector has been proposed (see, for example, Patent Document 1). Further, a method of directly attaching a metal lithium foil on the negative electrode mixture (for example, see Patent Document 2) and a method of forming a metal lithium layer by vapor deposition and transferring the metal lithium layer onto the negative electrode mixture layer are proposed. (For example, see Patent Document 3).

JP 2008-123826 A JP-A-11-283676 JP 2008-21901 A

  However, simply incorporating metal lithium into the electricity storage device may cause metal lithium pieces or metal lithium particles to be released into the electricity storage device when a portion of the metal lithium falls off the metal lithium foil or metal lithium layer. There is. Thus, the release of metal lithium pieces and metal lithium fine particles from the original location in the electricity storage device is a factor that reduces the safety of the electricity storage device due to internal short circuit of the electricity storage device and corrosion of the exterior material. It was. Further, when an abnormal situation occurs in which the power storage device opens due to an internal short circuit or overcharge, the dropped metal lithium pieces and metal lithium fine particles are scattered in the atmosphere. Furthermore, a part of the metallic lithium falling off and liberated from the negative electrode has been a factor of lowering the lithium ion doping amount and lowering the quality of the electricity storage device.

  An object of the present invention is to improve the safety and quality of an electricity storage device.

An electricity storage device of the present invention is an electricity storage device having a positive electrode comprising a positive electrode current collector and a positive electrode mixture layer and a negative electrode comprising a negative electrode current collector and a negative electrode mixture layer, wherein at least one of the negative electrodes is The negative electrode current collector is configured as a negative electrode composite material having an ion supply source in addition to the negative electrode current collector and the negative electrode composite material layer. The negative electrode composite material is accommodated in a bag-shaped separator, and the edge of the separator is closed over the entire circumference. is, the negative electrode current collector of the negative electrode mixture member is provided with a terminal welding portion projecting edges of the separator overlapping the terminal junction characterized Rukoto closed by heat-sealing or adhesion treatment.

  The electricity storage device of the present invention is characterized in that a plurality of through holes are formed in the positive electrode current collector and the negative electrode current collector.

A method for producing an electricity storage device of the present invention is a method for producing an electricity storage device having a positive electrode including a positive electrode current collector and a positive electrode mixture layer, and a negative electrode including a negative electrode current collector and a negative electrode mixture layer. A step of forming at least one negative electrode composite material including an ion supply source in addition to the negative electrode current collector and the negative electrode composite material layer; and housing the negative electrode composite material in a bag-shaped separator, the have a, a step of closing the entire circumference, the negative electrode current collector of the negative electrode mixture member is provided with a terminal welding portion projecting edges of the separator overlapping the terminal junction heat-sealing or adhesive It closed by process characterized Rukoto.

  In the present invention, the negative electrode composite material is accommodated in a bag-shaped separator. Therefore, even when the ion supply source is dropped from the negative electrode composite material, it is possible to prevent the ion supply source from being released from the vicinity of the negative electrode (negative electrode composite material) housed in the bag-shaped separator in the electricity storage device. It becomes possible. As a result, it is possible to prevent a short circuit of the power storage device and corrosion of the exterior material caused by diffusion of the ion supply source into the power storage device, and it is possible to improve the safety of the power storage device. In addition, since it is possible to keep metallic lithium in the bag-shaped separator, it is possible to prevent scattering of the ion supply source to the atmosphere when the situation where the electricity storage device opens, and the electricity storage device in an abnormal state It is possible to improve the safety of Furthermore, by storing the negative electrode (negative electrode composite material) in a bag-shaped separator, even if the ion supply source falls off from the negative electrode (negative electrode composite material), the ion supply is near the negative electrode (negative electrode composite material). It is possible to hold the source. As a result, the ion doping amount can be ensured as designed, and the performance degradation of the electricity storage device can be prevented. Moreover, since the ion supply source is provided on the negative electrode, the current collector for the ion supply source can be reduced. Thereby, it becomes possible to improve the energy density of an electrical storage device.

It is a perspective view which shows the electrical storage device which is one embodiment of this invention. It is sectional drawing which shows schematically the internal structure of an electrical storage device along the AA line of FIG. It is sectional drawing which expands and shows the internal structure of an electrical storage device partially. (A) is an exploded perspective view showing the internal structure of the negative electrode. (B) is a perspective view showing a negative electrode. It is sectional drawing which shows partially the internal structure of the electrical storage device which is other embodiment of this invention.

  FIG. 1 is a perspective view showing an electricity storage device 10 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the internal structure of the electricity storage device 10 along the line AA in FIG. As shown in FIGS. 1 and 2, an electrode stacking unit 12 is accommodated in an exterior material 11 configured using a laminate film. The electrode stacking unit 12 includes positive electrodes 13 and negative electrodes 14 and 15 that are alternately stacked. The negative electrode 15 disposed on the outermost part of the electrode laminate unit 12 is configured as a negative electrode composite material 26 integrally provided with a metal lithium foil 16 as an ion supply source. A separator 17 is sandwiched between the positive electrode 13 and the negative electrode 14. On the other hand, the negative electrode 15 is accommodated in a bag-shaped separator 18. Note that an electrolyte is injected into the exterior material 11. This electrolytic solution is composed of an aprotic polar solvent containing a lithium salt.

  FIG. 3 is a cross-sectional view showing a partially enlarged internal structure of the electricity storage device 10. As shown in FIG. 3, the positive electrode 13 has a positive electrode current collector 20 having a large number of through holes 20a. The positive electrode current collector 20 is provided with a positive electrode mixture layer 21. The positive electrode current collector 20 is provided with a terminal joint portion 20b extending in a convex shape. The plurality of terminal joint portions 20b are joined to each other in a stacked state. Further, the positive terminal 22 is joined to the terminal joint portion 20b.

  Similarly, the negative electrodes 14 and 15 have a negative electrode current collector 23 having a large number of through holes 23a. A negative electrode mixture layer 24 is provided on both surfaces of the negative electrode current collector 23 constituting the negative electrode 14. Further, a negative electrode mixture layer 24 is provided on one surface of the negative electrode current collector 23 constituting the negative electrode 15. Further, a metal lithium foil 16 is attached to the surface of the negative electrode current collector 23 constituting the negative electrode 15 on which the negative electrode mixture layer 24 is not provided, and the negative electrode composite material 26 is formed by the negative electrode 15 and the metal lithium foil 16. Is configured. Further, the negative electrode current collector 23 is provided with a terminal joint portion 23b extending in a convex shape. The plurality of terminal joining portions 23b are joined to each other in an overlapped state. Further, the negative electrode terminal 25 is bonded to the terminal bonding portion 23b.

  The positive electrode mixture layer 21 contains activated carbon as a positive electrode active material. This activated carbon can be reversibly doped and dedoped with lithium ions and anions. Further, the negative electrode mixture layer 24 includes polyacene organic semiconductor (PAS) as a negative electrode active material. This PAS can be reversibly doped / undoped with lithium ions. In this manner, by using activated carbon as the positive electrode active material and PAS as the negative electrode active material, the power storage device 10 illustrated functions as a lithium ion capacitor.

  The power storage device 10 to which the present invention is applied is not limited to a lithium ion capacitor, and may be a lithium ion secondary battery or an electric double layer capacitor. It may be a type of battery or a hybrid capacitor with these. Further, in this specification, doping (doping) means occlusion, support, adsorption, insertion, and the like. That is, dope means a state in which anions, lithium ions, and the like enter the positive electrode active material and the negative electrode active material. De-doping (de-doping) means release, desorption and the like. That is, dedoping means a state in which anions, lithium ions, and the like are emitted from the positive electrode active material and the negative electrode active material.

  As described above, the metal lithium foil 16 is attached to the negative electrode current collector 23 of the negative electrode 15. The negative electrode current collectors 23 of the negative electrodes 14 and 15 are joined to each other. That is, the metal lithium foil 16 and all the negative electrode mixture layers 24 are electrically connected. Therefore, by injecting the electrolytic solution into the exterior material 11, lithium ions are doped (hereinafter referred to as pre-doping) from the metal lithium foil 16 to the negative electrodes 14 and 15. Further, through holes 20 a and 23 a are formed in the positive electrode current collector 20 and the negative electrode current collector 23. For this reason, the lithium ions released from the metal lithium foil 16 pass through the through holes 20a and 23a of the current collectors 20 and 23 and move in the stacking direction. This makes it possible to smoothly pre-dope lithium ions for all the negative electrodes 14 and 15 to be stacked.

Thus, the negative electrode potential can be lowered by pre-doping lithium ions into the negative electrodes 14 and 15. Thereby, the cell voltage of the electricity storage device 10 can be increased. Moreover, it becomes possible to increase the electrostatic capacity of the negative electrodes 14 and 15 by pre-doping lithium ions into the negative electrodes 14 and 15. Thereby, the electrostatic capacity of the electricity storage device 10 can be increased. Furthermore, by increasing the capacitance of the negative electrodes 14 and 15, the potential range (potential difference) in which the positive electrode 13 operates can be expanded, and the cell capacity (discharge capacity) of the electricity storage device 10 can be increased. Thus, since the cell voltage, cell capacity, and electrostatic capacity of the electricity storage device 10 can be increased, the energy density of the electricity storage device 10 can be improved. Further, from the viewpoint of increasing the capacity of the electricity storage device 10, the metal lithium is adjusted so that the positive electrode potential after the positive electrode 13 and the negative electrodes 14 and 15 are short-circuited is 2.0 V (vs. Li ^/ Li ⁺ ) or less. It is preferable to set the amount of the foil 16.

  As shown in FIGS. 2 and 3, the configuration in which the negative electrode composite material 26 is disposed on the outermost part of the electrode laminated unit 12 has been described. However, the negative electrode composite material is sandwiched between the positive electrodes 13 located in the inner layer of the electrode laminated unit 12. You may arrange in. Further, the negative electrode composite material 26 may be arranged on the outermost part of the electrode laminated unit 12, and the negative electrode composite material may be arranged between the positive electrodes 13 located in the inner layer of the electrode laminated unit 12. Thus, the lithium ion doping rate can be increased by finely disposing the negative electrode composite material in the electrode stack unit 12 (power storage device 10). Moreover, about the negative electrode composite material for arrange | positioning in the inner layer of the electrode lamination | stacking unit 12, it is from a viewpoint of productivity that it adheres and comprises the metal lithium foil 16 on the negative electrode 14 provided with the negative electrode compound material layer 24 on both surfaces. preferable. However, disposing the negative electrode composite material in the inner layer of the electrode laminate unit 12 is disadvantageous in terms of work efficiency in the first place. Therefore, in consideration of work efficiency, the negative electrode composite material is disposed on the outermost part of the electrode laminate unit 12. It is preferable to arrange them. Therefore, in order to improve the working efficiency and increase the doping rate of lithium ions, a plurality of electrode laminate units having a negative electrode composite material arranged on the outermost part are produced, and then the plurality of electrode laminate units are laminated to store electricity. It is desirable to configure the device.

  Further, as shown in FIG. 3, the negative electrode composite material 26 disposed on the outermost part of the electrode laminate unit 12 is configured by attaching a metal lithium foil 16 to the uncoated surface of the negative electrode current collector 23. However, the negative electrode composite material to be disposed on the outermost part of the electrode laminate unit 12 may be configured by attaching the metal lithium foil 16 to the negative electrode 14 provided with the negative electrode mixture layer 24 on both surfaces. Thus, when the negative electrode composite material composed of the negative electrode 14 and the metal lithium foil 16 is disposed on the outermost part of the electrode laminate unit 12, it is preferable to dispose the surface on which the metal lithium foil 16 is provided facing outward. . This is because by arranging the metal lithium foil 16 facing outward, the metal lithium foil 16 can be easily brought into contact with the electrolytic solution and ionization can be easily achieved.

  However, disposing the negative electrode composite material provided with the two negative electrode mixture layers 24 at the outermost part of the electrode laminate unit 12 contributes to the negative electrode mixture layer 24 that does not face the positive electrode mixture layer 21, that is, charge / discharge. The difficult negative electrode mixture layer 24 is incorporated into the electricity storage device 10. This not only leads to an increase in the amount of electrolyte and cell weight and a decrease in energy density due to an increase in the volume of the electricity storage device, but also may disrupt the charge / discharge balance between the positive and negative electrodes in the electricity storage device 10. There is a risk of adversely affecting properties.

  On the other hand, as shown in FIG. 3, in order to dispose the negative electrode composite material 26 including the negative electrode 15 having the negative electrode mixture layer 24 on one side on the outermost part of the electrode laminate unit 12, the negative electrode mixture layer 24 is formed on both surfaces. In addition to manufacturing the provided negative electrode 14, it is necessary to manufacture the negative electrode 15 including the negative electrode mixture layer 24 on one side. That is, since it is necessary to manufacture two types of negative electrodes 14 and 15, it is not preferable in view of productivity. Also, in the laminating process of the electrode laminating unit 12, since the two types of negative electrodes 14 and 15 are used, the laminating operation becomes complicated, which is not preferable in view of productivity. From the above, the negative electrode composite material 26 including the negative electrode 15 having the negative electrode mixture layer 24 on one side is disposed on the outermost part of the electrode laminate unit 12, or the negative electrode 14 having the negative electrode mixture layer 24 on both sides is disposed. It is preferable to appropriately select whether the provided negative electrode composite material is disposed in consideration of the performance and productivity of the electricity storage device 10.

  In addition, although the structural example which arrange | positions the negative electrode 14 provided with the negative mix layer 24 on both surfaces in the outermost part of the electrode lamination | stacking unit 12 was described, it was not restricted to this, The positive mix layer 21 was provided on both surfaces The positive electrode 13 may be disposed on the outermost part of the electrode laminated unit 12. Thus, in the case where the electrode (positive electrode or negative electrode) provided with the electrode mixture layer (positive electrode mixture layer or negative electrode mixture layer) on both sides is arranged on the outermost part of the electrode laminate unit 12, It is preferable to arrange an electrode having a large capacity at the outermost part. That is, the capacity of the electricity storage device 10 is governed by the electrode having a small capacity of the positive electrode or the negative electrode, but by arranging this electrode in the inner layer of the electrode laminated unit 12, the small capacity of the electrode is left. The energy density of the electricity storage device 10 can be improved.

  Then, the negative electrode 15 with which the electrical storage device 10 of this invention is provided is demonstrated. FIG. 4A is an exploded perspective view showing the internal structure of the negative electrode composite material 26 accommodated in the bag-shaped separator 18. FIG. 4B is a perspective view showing the negative electrode composite material 26 accommodated in the bag-shaped separator 18. As shown in FIG. 3, the negative electrode current collector 23 has a large number of through holes 23a, but FIG. 4A shows the negative electrode current collector 23 with the through holes 23a omitted. Yes. As shown in FIG. 4A, a metallic lithium foil 16 is attached to one surface of the negative electrode current collector 23 of the negative electrode 15 constituting the negative electrode composite material 26. The negative electrode 15 to which the metal lithium foil 16 is attached, that is, the negative electrode composite material 26 is sandwiched between the pair of separators 18. Further, as shown by a one-dot chain line in FIG. 4B, the edge 18a of the separator 18 is closed over the entire circumference. In the above description, the negative electrode composite material 26 is sandwiched between the pair of separators 18 and then the edge 18a of the separator 18 is closed over the entire circumference. However, the present invention is not limited to this. For example, three sides of the edge portions 18a of the pair of separators 18 are closed to form the separator 18 in a bag shape, and after the negative electrode composite material 26 is inserted into the bag-shaped separator 18, the remaining open edge portion 18a is closed. Thus, the edge 18a of the separator 18 may be closed over the entire circumference. The procedure until the negative electrode composite material 26 is accommodated in the bag-shaped separator 18 may be appropriately determined.

  Examples of means for closing the edge 18a of the separator 18 include tape fastening with an adhesive tape, adhesion with a polymer adhesive, and the like. By using these means, the edge 18a of the separator 18 can be closed. When the material of the separator 18 includes a thermoplastic resin such as polyethylene or polypropylene, the edge portion 18a of the separator 18 can be closed by a heat sealing process in addition to the above means. Further, the edge 18a of the separator 18 may be closed by combining tape fastening with an adhesive tape, adhesion with a polymer adhesive, and heat fusion treatment. The negative electrode current collector 23 is provided with a terminal joint portion 23b extending in a convex shape. As means for closing the edge portion 18a of the separator 18 that overlaps the terminal joint portion 23b, it is preferable to use heat fusion treatment or adhesion using a polymer adhesive. By subjecting the edge portion 18 a to heat fusion treatment or adhesion treatment using a polymer adhesive, it is possible to insulate the surface of the terminal joint portion 23 b close to the negative electrode mixture layer 24. Thereby, precipitation of metallic lithium to the terminal joint part 23b accompanying a charging / discharging cycle can be suppressed.

  Thus, the negative electrode composite material 26 in which the metal lithium foil 16 and the negative electrode 15 are integrally formed is provided, and the negative electrode composite material 26 is covered with the bag-shaped separator 18. As a result, even when metallic lithium is dropped from the negative electrode current collector 23 of the negative electrode 15, the metallic lithium does not escape from the bag-shaped separator 18 that is closed over the entire circumference. This makes it possible to prevent the diffusion of metallic lithium. As a result, it is possible to prevent short circuit in the electricity storage device 10 and corrosion of the exterior material 11 caused by the liberated metallic lithium, and the safety of the electricity storage device 10 can be improved. Further, since it is possible to keep the metallic lithium in the bag-shaped separator 18, it is possible to prevent the metallic lithium from scattering into the atmosphere when the power storage device 10 is opened, and to store power in an abnormal state. The safety of the device 10 can be increased. Furthermore, even when metallic lithium is removed from the negative electrode current collector 23 of the negative electrode 15, the metallic lithium can be held in the vicinity of the negative electrode 15, so that the doping amount of lithium ions is ensured as designed. It becomes possible. Thereby, it becomes possible to prevent the capacity | capacitance fall and output fall of the electrical storage device 10. FIG. Furthermore, since the metal lithium foil 16 is supported by the negative electrode current collector 23, the lithium electrode current collector for holding the metal lithium foil 16 can be reduced. Thereby, since the weight and volume of the electrical storage device 10 can be reduced, the energy density of the electrical storage device 10 can be improved.

  In the above description, the plurality of through holes 20a and 23a are formed in the positive electrode current collector 20 and the negative electrode current collector 23. However, the negative electrode current collector and the positive electrode current collector having no through holes 20a and 23a are formed. The body may be used. Here, FIG. 5 is a cross-sectional view partially showing the internal structure of an electricity storage device 30 according to another embodiment of the present invention. In addition, about the member same as the member shown in FIG. 3, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 5, the electricity storage device 30 includes positive electrodes 31 and negative electrodes (negative electrode composite material) 32 that are alternately stacked. The positive electrode 31 includes a flat positive electrode current collector 33. The positive electrode current collector 33 is provided with the positive electrode mixture layer 21. The negative electrode 32 has a flat negative electrode current collector 34. The negative electrode current collector 34 is provided with a negative electrode mixture layer 24. Further, a metal lithium foil 35 as an ion supply source is attached on the negative electrode mixture layer 24 of the negative electrode 32. The negative electrode 32 including the metal lithium foil 35 is covered with a bag-shaped separator 18. In the outermost negative electrode 32, the negative electrode mixture layer 24 and the metal lithium foil 35 are provided only on one side (inner side) of the negative electrode current collector 34.

  As described above, when the metal lithium foil 35 is attached to all the negative electrode mixture layers 24, the positive electrode current collector 33 and the negative electrode current collector are used when all the negative electrode mixture layers 24 are doped with lithium ions. It is not necessary to move lithium ions in the stacking direction beyond 34. Thereby, a through-hole can be reduced from the positive electrode current collector 33 or the negative electrode current collector 34, the manufacturing cost of the positive electrode current collector 33 and the negative electrode current collector 34, the positive electrode mixture layer 21, and the negative electrode mixture layer Thus, the coating cost of 24 can be reduced. Even in such a negative electrode 32, by covering the negative electrode 32 with the bag-shaped separator 18, it is possible to prevent liberation of metallic lithium as in the case of the electricity storage device 10 described above. Thereby, the short circuit and the corrosion of the exterior material 11 caused by the liberated metallic lithium can be prevented, and the safety of the electricity storage device 30 can be improved. Further, since it is possible to keep the metallic lithium in the bag-shaped separator 18, it is possible to prevent the metallic lithium from scattering into the atmosphere when the power storage device 30 is opened, and to store power in an abnormal state. The safety of the device 30 can be increased. Furthermore, the doping amount of lithium ions can be ensured as designed, and the quality of the electricity storage device 30 can be improved.

  As shown in FIG. 3, the metal lithium foil 16 is directly attached to the negative electrode current collector 23. However, the present invention is not limited to this, and the negative electrode current collector 23 and the metal lithium foil 16 are not limited thereto. Between these, an auxiliary layer as described in JP-A-2001-15172 may be provided. By attaching the metal lithium foil 16 to the negative electrode current collector 23 via an auxiliary layer, it is possible to suppress an increase in electrode resistance accompanying the attachment of the metal lithium foil 16. Further, as shown in FIG. 5, the metal lithium foil 35 is directly attached to the negative electrode mixture layer 24. However, the present invention is not limited to this, and the negative electrode mixture layer 24 and the metal lithium foil 35 are not limited thereto. Between these, an auxiliary layer as described in JP-A-2001-15172 may be provided. By attaching the metal lithium foil 35 to the negative electrode mixture layer 24 via the auxiliary layer, it is possible to suppress an increase in electrode resistance accompanying the attachment of the metal lithium foil 35.

  Hereinafter, the components of the electricity storage device described above will be described in detail in the following order. [A] positive electrode, [B] negative electrode, [C] positive electrode current collector and negative electrode current collector, [D] ion supply source, [E] separator, [F] electrolyte solution, [G] exterior material.

[A] Positive Electrode The positive electrode has a positive electrode current collector and a positive electrode mixture layer integrated therewith. When the electric storage device functions as a lithium ion capacitor, it is possible to employ a material capable of reversibly doping and dedoping lithium ions and / or anions as the positive electrode active material contained in the positive electrode mixture layer. . That is, there is no particular limitation as long as it is a substance capable of reversibly doping and dedoping at least one of lithium ions and anions. For example, activated carbon, a metal oxide such as RuO ₂ , a conductive polymer, a polyacene-based material, or the like can be used.

For example, the activated carbon is preferably formed from activated carbon particles having an alkali activation treatment and a specific surface area of 600 m ² / g or more. As a raw material for the activated carbon, phenol resin, petroleum pitch, petroleum coke, coconut shell, coal-based coke and the like are used. Phenol resin and coal-based coke are preferable because the specific surface area can be increased. The alkali activator used for the alkali activation treatment of these activated carbons is preferably an alkali metal hydroxide salt such as lithium, sodium or potassium. Of these, potassium hydroxide and sodium hydroxide are preferred. Examples of the alkali activation method include a method in which a carbide and an activator are mixed and then heated in an inert gas stream. Further, there is a method in which an activation agent is supported on the raw material of activated carbon in advance and then heated to perform carbonization and activation processes. Furthermore, after activating carbide by a gas activation method such as water vapor, a method of surface treatment with an alkali activating agent is also included. The activated carbon that has been subjected to such alkali activation treatment is subjected to removal of residual ash and pH adjustment by washing, and then pulverized using a known pulverizer such as a ball mill. As the particle size of the activated carbon, a wide range of commonly used materials can be used. For example, D50% is 2 μm or more, preferably 2 to 50 μm, and most preferably 2 to 20 μm. The average pore diameter is preferably 1.5 nm or more. The specific surface area is preferably 600 to 3000 m ² / g. Among them, 1500 m ² / g or more, and particularly it is preferable that a 1800~2600m ² / g.

In addition, when the power storage device functions as a lithium ion secondary battery, the positive electrode active material contained in the positive electrode mixture layer can be reversibly doped / dedoped with a conductive polymer such as polyaniline or lithium ions. It is possible to adopt a substance. For example, vanadium pentoxide (V ₂ O ₅ ) or lithium cobaltate (LiCoO ₂ ) can be used as the positive electrode active material. In addition, Li _X M _Y O _Z such as Li _X CoO ₂ , Li _X NiO ₂ , Li _X MnO ₂ , and Li _X FeO ₂ (x, y, z are positive numbers, M is a metal, two or more types It is also possible to use lithium-containing metal oxides that can be represented by the general formula (1), transition metal oxides such as cobalt, manganese, vanadium, titanium, nickel, or sulfides. In particular, when a high voltage is required, it is preferable to use a lithium-containing metal oxide having a potential of 4 V or more with respect to metal lithium. For example, lithium-containing cobalt oxide, lithium-containing nickel oxide, or lithium-containing cobalt-nickel composite oxide is particularly suitable. When safety is required, it is preferable to use a material that does not easily release oxygen from the structure even in a high temperature environment. For example, lithium iron phosphate, lithium iron silicate, vanadium oxide, and the like can be given. In addition, the positive electrode active material illustrated above may be used independently according to a use and a specification suitably, and may be used in mixture of multiple types.

  The positive electrode active material such as activated carbon described above is formed into a powder form, a granular form, a short fiber form, or the like. An electrode slurry is formed by dispersing the positive electrode active material and the binder in a solvent. Then, a positive electrode mixture layer is formed on the positive electrode current collector by applying and drying an electrode slurry containing the positive electrode active material on the positive electrode current collector. Examples of the binder mixed with the positive electrode active material include rubber-based binders such as SBR, fluorine-containing resins such as polytetrafluoroethylene and polyvinylidene fluoride, thermoplastic resins such as polypropylene, polyethylene, and polyacrylate, polyvinyl Alcohol can be used. As the solvent, for example, water or N-methyl-2-pyrrolidone can be used. In addition, a conductive material such as acetylene black, graphite, ketjen black, carbon black, or metal powder may be appropriately added to the positive electrode mixture layer.

[B] Negative Electrode The negative electrode has a negative electrode current collector and a negative electrode mixture layer integrated therewith. The negative electrode active material contained in the negative electrode mixture layer is not particularly limited as long as it can reversibly dope and dedope lithium ions. For example, alloy materials such as tin and silicon, oxides such as silicon oxide, tin oxide, lithium titanate, vanadium oxide, graphite (graphite), graphitizable carbon, hard carbon (non-graphitizable carbon) ) And other carbon materials, polyacene-based substances, and the like can be used. Lithium titanate is preferable as the negative electrode active material because it has excellent cycle characteristics. Tin, tin oxide, silicon, silicon oxide, graphite, and the like are preferable as the negative electrode active material because the capacity can be increased. In addition, a polyacene organic semiconductor (PAS), which is a heat-treated product of an aromatic condensation polymer, is suitable as a negative electrode active material because the capacity can be increased. This PAS has a polyacene skeleton structure. The hydrogen atom / carbon atom number ratio (H / C) of the PAS is preferably in the range of 0.05 to 0.50. When H / C of PAS exceeds 0.50, the aromatic polycyclic structure is not sufficiently developed, so that lithium ions are not doped and undoped smoothly, and the charge / discharge efficiency of the electricity storage device May decrease. When the H / C of PAS is less than 0.05, the capacity of the electricity storage device may be reduced. In addition, the negative electrode active material illustrated above may be used independently according to a use and a specification suitably, and may be used in mixture of multiple types.

  The negative electrode active material such as PAS described above is formed into a powder form, a granular form, a short fiber form, or the like. An electrode slurry is formed by dispersing the negative electrode active material, a binder, and a solvent. Then, the electrode slurry containing the negative electrode active material is applied to the negative electrode current collector and dried to form a negative electrode mixture layer on the negative electrode current collector. Examples of the binder mixed with the negative electrode active material include fluorine-containing resins such as polytetrafluoroethylene and polyvinylidene fluoride, thermoplastic resins such as polypropylene, polyethylene, and polyacrylate, polyvinyl alcohol, and carboxymethyl cellulose (CMC). ), Styrene-butadiene rubber (SBR), ethylene-propylene-diene copolymer (EPDM), and the like can be used. Among these, it is preferable to use an SBR rubber binder because high adhesiveness can be expressed with a small amount of addition. As the solvent, water, N-methyl-2-pyrrolidone, or the like can be used. In addition, a conductive material such as acetylene black, graphite, expanded graphite, carbon nanotube, vapor-grown carbon fiber, carbon black, carbon fiber, and metal powder may be added as appropriate to the negative electrode mixture layer.

[C] Positive electrode current collector and negative electrode current collector As materials for the positive electrode current collector and the negative electrode current collector, various materials generally proposed for batteries and electric double layer capacitors can be used. For example, aluminum, stainless steel, or the like can be used as a material for the positive electrode current collector. Stainless steel, copper, nickel, or the like can be used as a material for the negative electrode current collector. Moreover, when forming a through-hole in a positive electrode collector or a negative electrode collector, the opening rate of a through-hole is usually 40 to 60%. Note that the size, number, shape, and the like of the through holes are not particularly limited as long as they do not hinder the movement of lithium ions.

[D] Ion supply source Although the metal lithium foil is provided as the ion supply source, a lithium-aluminum alloy or the like may be used as the ion supply source. In the above description, a metal lithium foil obtained by rolling metal lithium is used. However, the present invention is not limited to this, and a metal lithium layer is formed on the negative electrode current collector or the negative electrode mixture layer by vapor deposition. Also good. Furthermore, an ion supply source may be provided for the negative electrode as the negative electrode composite material by including fine granular metallic lithium as an ion supply source in the negative electrode mixture layer.

[E] Separator As a separator, it has high ion permeability (air permeability), predetermined mechanical strength, durability against electrolyte solution, positive electrode active material, negative electrode active material, and the like, and has an insulating hole. A porous body or the like can be used. For example, paper (cellulose), glass fiber, polyethylene, polypropylene, polystyrene, polyester, polytetrafluoroethylene, polyvinylidene difluoride, polyimide, polyphenylene sulfide, polyamide, polyamideimide, polyethylene terephthalate, polybutylene terephthalate, polyetheretherketone For example, a cloth, a nonwoven fabric or a microporous body having a gap composed of the like is used.

  Moreover, when closing the separator, it is possible to use a pressure-sensitive adhesive tape or a polymer adhesive, but these pressure-sensitive adhesive tape or polymer adhesive does not dissolve in the electrolyte solution, and the electrolyte solution and the positive electrode active material In addition, it is preferably chemically and electrochemically stable with respect to the negative electrode active material and the like. As an adhesive tape, a polyimide adhesive tape etc. are mentioned, for example. The polymer used as the polymer adhesive is preferably a thermoplastic polymer. Specific examples include polyolefins such as polyethylene and polypropylene, polyethylene terephthalate, polyester, polyvinylidene fluoride, and polyethylene oxide. It is done. As an adhesion method, for example, a method in which a polymer adhesive is dissolved in a solvent and applied to the edge of the separator and then the solvent is removed by heating or depressurizing operation while applying pressure to the adhesive portion, or For example, a method may be used in which a polymer film containing the polymer adhesive is disposed on the edge of a separator and is bonded by heat and pressure. In particular, it is preferable to use polyvinylidene fluoride or polyethylene oxide having lithium ion conductivity because the deterioration of the electrode characteristics can be suppressed even when a polymer adhesive adheres to the electrode mixture layer. As a solvent for dissolving the polymer adhesive, it is desirable to use an organic solvent having a boiling point of 200 ° C. or less. Depending on the solubility with the polymer adhesive used, specific examples of the solvent include dimethylformamide and acetone. When the boiling point of the organic solvent exceeds 200 ° C., heating at about 100 ° C. is not preferable because it takes a long time to remove the solvent. Further, heating to 200 ° C. or higher is not preferable for safety because metallic lithium is present in the vicinity of the separator bonding portion. For the above reasons, the boiling point of the organic solvent is preferably 200 ° C. or lower, more preferably 180 ° C. or lower.

  In addition, by including these materials exemplified as polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyester and the like in the separator, it is possible to perform a heat-sealing treatment and close the separator. The heat fusion conditions of the separator are determined by appropriately examining the heating temperature and the heating time. The heating temperature of the separator is preferably close to the melting temperature of the separator. The specific melting temperature varies depending on the material and configuration of the separator. For example, a microporous separator made of polyethylene and polypropylene owned by the inventors melts at around 110 ° C. Accordingly, when the separator is heat-sealed, the heat-sealing condition is determined by fusing the separator while changing the heating temperature and heating time at a temperature of about 110 ° C. and confirming the adhesive strength. If the heating time is short or the melting temperature is low, the separator is not sufficiently melted and insufficient adhesion is not preferable. Further, it is not preferable that the heating time is long or the melting temperature is high because the separator is bent or the separator melts to a portion in contact with the electrode composite surface to increase the resistance of the electricity storage device.

  Moreover, it is preferable that the air permeability of a separator is 5 second / 100 mL or more and 600 second / 100 mL or less. The air permeability means time (seconds) required for 100 mL of air to pass through the porous sheet. When the air permeability exceeds 600 seconds / 100 mL, it is difficult to obtain a high lithium ion mobility in the separator, which is not preferable because it impedes the lithium ion pre-doping rate. An air permeability of less than 5 seconds / 100 mL is not preferable because the strength of the separator becomes insufficient. The air permeability of the separator is more preferably 30 seconds / 100 mL to 500 seconds / 100 mL.

  The separator preferably has a porosity of 30% to 90%. When the porosity of the separator is less than 30%, the amount of electrolyte retained in the separator is reduced and the internal resistance of the electricity storage device is increased, which is not preferable. Further, if the porosity of the separator exceeds 90% or more, it is not preferable because sufficient separator strength cannot be obtained. The porosity of the separator is more preferably 35% to 80%.

  The thickness of the separator is preferably 5 μm to 100 μm. A thickness exceeding 100 μm is not preferable because the distance between the positive and negative electrodes increases and the internal resistance increases. On the other hand, when the thickness is less than 5 μm, the strength of the separator is remarkably lowered and an internal short circuit is easily generated, which is not preferable. The thickness of the separator is more preferably 10 μm or more and 30 μm or less.

  In addition, when the internal temperature of the electricity storage device reaches or exceeds the upper limit temperature of the specification, it is possible to provide the separator with the characteristic that the separator gap is closed by the melting of the separator components (separator shutdown function). Preferred for. The blockage start temperature is usually 90 ° C. or higher and 180 ° C. or lower, although it depends on the specifications of the electricity storage device. When a material such as polyimide that has high heat resistance and is difficult to melt at the above temperature is used for the separator, it is preferable to mix a material that can be melted at the above temperature such as polyethylene. The term “mixing” as used herein includes not only simple mixing of a plurality of materials, but also means that two or more types of separators having different materials are stacked, copolymerization of separator materials, and the like. Note that a separator having a small thermal shrinkage even when the internal temperature of the electricity storage device exceeds the specified upper limit temperature is more preferable in terms of safety of the electricity storage device.

  As described above, the exemplified separators may be used singly according to the application and specifications, or the same type of separators may be used in an overlapping manner. A plurality of types of separators may be used in an overlapping manner.

[F] Electrolytic Solution As the electrolytic solution, it is preferable to use an aprotic polar solvent containing a lithium salt from the viewpoint that electrolysis does not occur even at a high voltage and that lithium ions can exist stably. Examples of the aprotic polar solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, dioxolane, methylene chloride, sulfolane and the like. Or the mixed solvent is mentioned. Propylene carbonate is preferably used from the viewpoint of the relative permittivity contributing to the charge / discharge characteristics, the freezing point and boiling point contributing to the operating temperature range of the electricity storage device, and the flash point contributing to safety. However, when graphite is used as the negative electrode active material, propylene carbonate decomposes on graphite when the negative electrode potential is about 0.8 V (vs. Li ^/ Li ⁺ ), so ethylene carbonate is used as an alternative solvent. It is preferable to do. Ethylene carbonate has a melting point of 36 ° C. and is solid at room temperature. For this reason, when using ethylene carbonate as a solvent for an electrolytic solution, it is essential to mix it with an aprotic polar solvent other than ethylene carbonate. In addition, the aprotic polar solvent used in combination with ethylene carbonate has a low viscosity and a low freezing point, such as diethyl carbonate and ethyl methyl carbonate, from the viewpoint of charge / discharge characteristics and the operating temperature range of the electricity storage device. It is preferred to select a solvent. However, an electrolyte solution composed of ethylene carbonate and an aprotic polar solvent having a low viscosity and a low freezing point, such as diethyl carbonate, has a rapid ion conduction due to the solidification of ethylene carbonate when the ambient temperature is about −10 ° C. or lower. Low temperature characteristics are not good because it causes a decrease in temperature. Therefore, in order to improve the low temperature characteristics, it is preferable to include the above-mentioned propylene carbonate in the solvent of the electrolytic solution, and when graphite is used for the negative electrode active material and the conductive material, graphite having low reductive decomposability of propylene carbonate is used. It is preferable.

Examples of the lithium salt include LiClO ₄ , LiAsF ₆ , LiBF ₄ , LiPF ₆ , and LIN (C ₂ F ₅ SO ₂ ) ₂ . The electrolyte concentration in the electrolytic solution is preferably at least 0.1 mol / L or more in order to reduce the internal resistance due to the electrolytic solution. Furthermore, it is preferable to set it within the range of 0.5-1.5 mol / L. The lithium salts may be used alone or in combination.

Note that vinylene carbonate (VC), ethylene sulfite (ES), fluoroethylene carbonate (FEC), and derivatives thereof may be added to the electrolytic solution as additives for improving characteristics. The addition amount is preferably in the range of 0.01 to 10% by volume. Further, as an additive for making the electricity storage device flame-retardant, a substance such as a phosphazene compound or a derivative thereof, a fluorinated carboxylic acid ester, or a fluorinated phosphoric acid ester may be added to the electrolytic solution. Examples of the flame retardant additive include phoslite (manufactured by Nippon Chemical Industry Co., Ltd.), (CF ₃ CH ₂ O) ₃ PO, (HCF ₂ CF ₂ CH ₂ O) ₂ CO, and the like.

Further, an ionic liquid (ionic liquid) may be used instead of the organic solvent. As the ionic liquid, combinations of various cationic species and anionic species have been proposed. Examples of the cationic species include N-methyl-N-propylpiperidinium (PP13), 1-ethyl-3-methylimidazolium (EMI), diethylmethyl-2-methoxyethylammonium (DEME), and the like. Examples of the anion species include bis (fluorosulfonyl) imide (FSI), bis (trifluoromethanesulfonyl) imide (TFSI), PF ₆ ⁻ , BF ₄ ^{− and the} like.

[G] Exterior Material As the exterior material, various materials generally used for batteries can be used. For example, a metal material such as iron or aluminum may be used. Moreover, you may use film materials, such as resin. Further, the shape of the exterior material is not particularly limited. It can be appropriately selected depending on the application such as a cylindrical shape or a rectangular shape. From the viewpoint of reducing the size and weight of the electricity storage device, it is preferable to use a film-type exterior material using an aluminum laminate film. In general, a three-layer laminate film having a nylon film on the outside, an aluminum foil in the center, and an adhesive layer such as modified polypropylene on the inside is used.

  As mentioned above, although this invention was demonstrated in detail based on drawing, this invention is not limited to the said embodiment, It cannot be overemphasized that it can change variously in the range which does not deviate from the summary. For example, the structure of the electricity storage device of the present invention can be applied not only to lithium ion secondary batteries and lithium ion capacitors, but also to various types of batteries such as magnesium ion secondary batteries and hybrid capacitors thereof.

(Example)
The effectiveness of the present invention was verified using the electricity storage device having the above-described configuration. A lithium ion capacitor was used as the electricity storage device. This lithium ion capacitor has a configuration in which a negative electrode composite material in which a metal lithium foil is bonded on the negative electrode is provided at the outermost part of the electrode stack unit, and the edge of the separator sandwiching the negative electrode composite material is closed over the entire circumference. doing. Such a lithium ion capacitor was produced as follows.

[Production method of positive electrode]
Activated carbon having a BET specific surface area of 2200 m ² / g was obtained by alkali activation of the phenol resin. This activated carbon was thoroughly washed to remove residual ash and adjust pH. The activated carbon thus produced was used as a positive electrode active material.

  A paste was prepared by kneading 100 parts by weight of the positive electrode active material, 6 parts by weight of acetylene black manufactured by Denki Kagaku Kogyo Co., Ltd., and 4 parts by weight of carboxymethyl cellulose with water. The positive electrode slurry was prepared by adding the emulsion of an acrylate-type rubber binder to this paste so that it might become 6 weight part as solid content, and adding water, and adjusting a viscosity. This positive electrode slurry was applied to both surfaces of an aluminum foil having a through hole to obtain a positive electrode.

[Production method of negative electrode]
88 parts by weight of a non-graphitizable carbon carbotron PS (F) manufactured by Kureha Co., Ltd. as a negative electrode active material, 6 parts by weight of an acetylene black special press product HS-100 manufactured by Denki Kagaku Kogyo Co., Ltd., sodium carboxymethylcellulose A paste was prepared by kneading 3 parts by weight of salt with water. To this paste, a latex of styrene butadiene dirubber binder was added to a solid content of 4 parts by weight, and water was added to adjust the viscosity to prepare a negative electrode slurry. The negative electrode slurry was applied to both surfaces of a copper expanded metal having through holes to obtain a negative electrode.

[Cell fabrication method]
Each of the positive electrode and the negative electrode obtained as described above was dried under reduced pressure. After drying, 14 positive electrodes having a size of the composite portion of 3.8 cm × 2.4 cm and 15 negative electrodes having a size of the composite portion of 4.0 cm × 2.6 cm were cut out. Next, 30 paper separators having a thickness of 4.6 μm × 3.2 cm with a thickness of 35 μm were cut out. Of the positive electrodes, negative electrodes, and separators prepared as described above, 14 positive electrodes, 13 negative electrodes, and 26 separators become positive electrodes, separators, negative electrodes, separators, positive electrodes, separators, negative electrodes... The electrode lamination unit was produced by laminating.

Next, in the electrode laminated unit, the negative electrode potential when cut into a size of 3.8 cm × 2.4 cm and applied to a voltage of 3.8 V between the positive and negative electrodes after lithium ion pre-doping is 20 mV (vs. Li A negative electrode composite material was prepared by sticking a metal lithium foil having a weight half of the weight of / Li ⁺ ) to one surface of a negative electrode that was not used for electrode lamination. Then, two separators that were not used for electrode lamination were arranged on both sides of the negative electrode composite material, and a polyethylene film having a thickness of 30 μm and a width of 2 mm was interposed between the separators sandwiching the negative electrode composite material and the edge of the separator It was installed all around. Next, by using a chamber type degassing sealer FCB-200 manufactured by Fuji Impulse Co., Ltd., the edge of the separator sandwiching the polyethylene film was subjected to heat and pressure to close the edge of the separator. By repeating this heat-pressing operation, the negative electrode composite material was accommodated in a bag-shaped separator whose edge was closed over the entire circumference. Further, by repeating this operation, two separator composites of the negative electrode composite material were produced.

  Subsequently, the electrode laminate unit including the lithium ion supply source was completed by disposing two separator composites of the negative electrode composite material on both outermost sides of the electrode laminate unit. In addition, about the negative electrode composite material arrange | positioned at the outermost part of the said electrode laminated unit, it has arrange | positioned so that metal lithium foil may become the outermost layer of an electrode laminated unit. Furthermore, the positive electrode terminal was disposed and welded to the terminal joint portion of the positive electrode current collector, and the negative electrode terminal was disposed and welded to the terminal joint portion of the negative electrode current collector.

  Next, as a reference electrode for measuring the positive and negative electrode potentials in the electricity storage device, a metal lithium foil was crimped to a stainless mesh having a thickness of 120 μm, and a nickel terminal was welded to the stainless mesh to produce a lithium electrode. . Then, the lithium electrode is disposed on the outermost one surface of the electrode laminate unit including the lithium ion supply source, and the outer periphery of the electrode laminate unit and the potential reference lithium electrode is covered with a paper separator having a thickness of 35 μm. The overlapped portion was stopped with a polyimide adhesive tape to complete a lithium ion capacitor element.

Next, the lithium ion capacitor element was covered with an aluminum laminate film as an exterior material, and three sides of the aluminum laminate film were heated and fused. Thereafter, an electrolytic solution prepared by dissolving LiPF ₆ in propylene carbonate so as to have a concentration of 1.2 mol / L was poured into an aluminum laminate film and impregnated through a vacuum impregnation step. And 100 cells of the lithium ion capacitor used as an Example were produced by vacuum-sealing the remaining one side of an aluminum laminate film.

(Comparative example)
100 cells of a lithium ion capacitor serving as a comparative example were produced in the same manner as the lithium ion capacitor of the example except that the ends of the pair of separators arranged so as to sandwich the negative electrode composite material were not closed.

(Examination of Examples and Comparative Examples)
Lithium ion pre-doping was terminated by allowing the lithium ion capacitor cells produced in Examples and Comparative Examples to stand at room temperature for 2 weeks. 34 cells of the comparative example were expanded and became defective cells. When the potentials of the positive electrode and the negative electrode were confirmed using the lithium electrode, it was confirmed that the potential of the positive electrode was significantly lower than 2 V (vs. Li ^/ Li ⁺ ). It is considered that a metal lithium piece dropped from the metal lithium comes into contact with the positive electrode (short circuit), and the positive electrode potential is lowered, so that gas resulting from reductive decomposition of the electrolytic solution is generated on the positive electrode. On the other hand, in the cell of the example, the cell in the above-described state was not seen at all. Table 1 shows the results of measuring the cell voltage, positive electrode potential, and negative electrode potential of 100 cells of the example in which no cell expansion was observed and 66 cells of the comparative example. Although the cell of the example has a larger number of measurement samples, it can be confirmed that variations in cell voltage, positive electrode potential, and negative electrode potential are smaller. In the cell of the comparative example, it is presumed that there is a cell that does not reach the cell expansion but may cause the micro short circuit.

  Next, 10 cells were arbitrarily extracted from the cells of the example and the comparative example, and the inside of the cell was investigated by disassembling the cell. About the cell of the comparative example, it was confirmed that the microparticles | fine-particles which have the metallic luster considered to be metallic lithium exist from electrolyte solution other than the place which installed the negative electrode composite material, or the electrode laminated unit. Accordingly, it can be seen that the cell of the comparative example has a risk that the predetermined lithium ion pre-doping amount cannot be doped into the negative electrode due to liberation of metallic lithium and that the cell suddenly shorts. On the other hand, the presence of a substance considered to be metallic lithium was not recognized from the cell of the example. From the above, it has been shown that the cell of the example constituting the embodiment of the present invention is excellent in quality.

DESCRIPTION OF SYMBOLS 10 Power storage device 13 Positive electrode 14 Negative electrode 15 Negative electrode 16 Metal lithium foil (ion supply source)
18 Separator 20 Positive electrode current collector 20a Through hole 21 Positive electrode composite material layer 23 Negative electrode current collector 23a Through hole 24 Negative electrode composite material layer 26 Negative electrode composite material 30 Power storage device 31 Positive electrode 32 Negative electrode (negative electrode composite material)
33 Positive electrode current collector 34 Negative electrode current collector 35 Metal lithium foil (ion source)

Claims (3)

An electricity storage device having a positive electrode including a positive electrode current collector and a positive electrode mixture layer and a negative electrode including a negative electrode current collector and a negative electrode mixture layer,
At least one of the negative electrodes is configured as a negative electrode composite material including an ion supply source in addition to the negative electrode current collector and the negative electrode mixture layer,
The negative electrode composite material is accommodated in a bag-shaped separator, and the edge of the separator is closed over the entire circumference .
Storage device wherein the negative electrode current collector of the negative electrode mixture member is provided with a terminal welding portion projecting edges of the separator overlapping the terminal junction, wherein Rukoto closed by heat sealing process or adhesive process. The electricity storage device according to claim 1, wherein
A power storage device, wherein the positive electrode current collector and the negative electrode current collector are formed with a plurality of through holes. A method for producing an electricity storage device having a positive electrode comprising a positive electrode current collector and a positive electrode mixture layer and a negative electrode comprising a negative electrode current collector and a negative electrode mixture layer,
A step of forming at least one of the negative electrodes into a negative electrode composite material including an ion supply source in addition to the negative electrode current collector and the negative electrode mixture layer;
The negative electrode mixture member is accommodated in a bag-like separator, have a, a step of closing over the edge of the separator the entire circumference,
The negative electrode current collector of the negative electrode mixture member is provided with a terminal welding portion projecting, producing the electric storage device the edge of the separator overlapping the terminal junction, wherein Rukoto closed by heat-sealing or adhesion treatment Method.

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